[incr Tcl] is an object-oriented extension of the Tcl language. It
was created to support more structured programming in Tcl. Tcl scripts
that grow beyond a few thousand lines become extremely difficult to
maintain. This is because the building blocks of vanilla Tcl are
procedures and global variables, and all of these building blocks
must reside in a single global namespace. There is no support for
protection or encapsulation.
